In METABRIC cohort, similar association was observed at the mRNA level, with high SLC39A6 expression was associated with low tumour grade (P < 0.0001 and P = 0.006) and good NPI scores (all P < 0.0001) in both the entire BC cohort and the ER + subgroup (Supplementary Table 5). Here, SLC39A6 is linked to neoplasm.